最大连续子串和的逐步优化

算法渣渣。。。。没办法，从最简单的慢慢学起吧。。。哎

恩，函数基本都在20行左右~

假设全部为负数时，最大连续子串和为 0;
start, end 记录最大连续子串和的头尾。

#include<iostream>#include<cstdio>using namespace std;const int maxn=100005;int a[maxn];int maxSubsequenceSum(int a[], int &size, int &start, int &end){    int maxSum = 0;    int startTemp = 0;    int currentSum = 0;    for(int i = 0; i < size; i++){        currentSum += a[i];        if(currentSum < 0){            startTemp = i + 1;            currentSum = 0;        }        if(currentSum > maxSum){            maxSum = currentSum;            start = startTemp;            end = i;        }    }    return maxSum;}int main(){int t, n;cin >> t;for(int m = 1; m <= t; m++){cin >> n;int tag = 0;for(int i = 0; i < n; i++){scanf("%d", &a[i]);if(a[i] > 0)tag = 1;}cout << "Case " << m << ":" << endl;int start = 0, end = 0, ans;if(tag)//含有正数的情况ans = maxSubsequenceSum(a, n, start, end);else{//考虑全部非正的特殊情况ans = a[0];for(int i = 1; i < n; i++){if(a[i] > ans){ans = a[i];start = i; end = i;}}}cout << ans <<" "<< start + 1 <<" "<< end + 1 << endl;if(m != t)cout << endl;}return 0;}